Pump piston



G. C. WELLS PUMP PI'STON June 20, "1939.

Filed July 6, 1937 k A z /Nl/ENTOR GEORGE C. WLL6 HARRIS,

ATTORNEYS.

Patented June 20, 393

f. T E S PUMP PISTON -Application July 6, 1937, Serial No. 151,997

5 (Jlaims.

My invention relates to pump pistons with particular reference topistons employed in slush pumps and the like.

The type of piston involved here comprises a piston body of resilientmaterial incorporating a metal core that is apertured to receive apiston rod. The metal core is subject to practically no wear, but everystroke of a slush pump involves abrasion of the piston body. One of theobjects of my invention is to provide a separable core for such a pistonwhereby the piston body may be replaced, the value of the core not beinincluded'in the replacement cost.

Another object of my invention is to provide a core construction that ina given size may be combined with a number of sizes of piston bodies. Inthe operation of a slush pump it is commonly found advisable toreduce'the diameter of the pump cylinder by inserting a new liner.- Byvirtue of my construction it is necessary, in such a case, to changeonly the piston body to the new diameter, the original piston core beingretained. It will .be apparent that by constructing such a core to flt anumber of different body sizes, I obtain a substantial reduction in thenumber of core sizes that must be manufactured and stocked toaccommodate slush pumps ofvarious diameters,

Another object of my invention is to provide an interlocking pistonstructure that may be readily assembled or dismantled progressively fromone end of the piston, whereby the procedure of changing piston bodiesmay be'greatly simplified. It is contemplated that the pistonconstruction will permit a change of piston bodies without removal ofthe piston rod from the pump cylinder.

In the interlocked assemblage, flanges are in engagement withcomplementary recesses. A

feature of my piston is that each of the recesses is formed by thejuxtaposition of cooperative members whereby the flange complementary tothe recess may be readily engaged or disengaged by axial movement in theassembling or dismantling of the piston.

'A further object of my invention is to provide an assemblage ofinterlocking members that will provide the strength and rigidity of anintegral core casting and that will transmit and distribute forces fromthe pump rod into the interior of the piston body in a direct manner.

A still further object of my invention is to provide a split piston bodywith internal reinforcing means to lend rigidity to portions of thepiston body adjacent the plane of the split.

The above and other objects of my invention will be apparent from thefollowing detailed description.

In the drawing which is to be taken as illustrative only:

Fig. 1 is an axial section through one form of my piston.

Fig. 2 is an exploded view of the piston with one member shown inphantom to reveal the construction of an embedded reinforcement 10member.

Figs. 3 and 4 indicate in an exaggerated manner how one core assemblymay be employed with difierent sizes of piston bodies, and

Fig. 5 is a modification of my invention adapt- 15 ed for mounting ontapered piston rods.

In Fig. 1 a piston rod I0 is provided, in a well known manner, with anintegral flange l I having a conical shoulder l2 on one face thereof.The

end of the piston rod is provided with threads I3 20 for receiving a nutl4 that is similar in configuration to the flange H and has a conicalshoulder l5 similar to the shoulder l2. The piston proper comprises acore assembly, generally designated 3, on which is mounted a piston bodygenerally 25 designated I9, the piston body being fabricated of rubberor other suitable resilient material.

In the preferred form of my invention the core assembly comprises threepieces: a hub member 20 at one end of the piston, a similar hub mem- 30her 2| at the other end of the piston, and an intermediate annularmember 22. The hub member 20 base cylindrical portion 23 and an integralend flange 2 3 that is turned axially inwardly to grip the piston bodyl9. In a similar 35 interlocking relationships maybe provided by 40 thejuxtaposition of cooperating members. In the preferred form of myinvention, for example, the intermediate annular member 22 has a centralradial flange 29 and two cylindrical portions 30 and 3| on oppositesides of the flange, 45

these cylindrical portions being smaller in diameter than theadjacentcylindrical portions 23 and 25 of the hub members 20 and 2|. It will beapparent that'the cylindrical portions 23 and 30 together with theflange 29 form cooperatively so an annular recess 32, and that thecylindrical portions 25 and 3i together with the flange 29 form a secondannular recess 33.

To provide the desired character of interlock,-

ing relationship between the body 19 and the core 55 assemblagedescribed, the body is divided into two complementary members 35 and 35,the member 35 having an inwardly directed flange 3'! complementary tothe recess 32, and the member 36 having a similar inwardly directedflange 38 complementary to the recess 33.

In the preferred form of my invention, permanently embedded in the bodymembers 35 and 35 respectively, are rigid reinforcing means 40 and 4|adapted to interlock with the core assembly to serve, in effect, asintegral parts thereof. In the construction shown in the drawing, thesereinforcing means are in the form of metal rings, each having aplurality of holes 42, and these rings are so placed in the two pistonbodies that they provide the material for the flanges 31 and 38.

By employing a plurality of reinforcing means, as exemplified by thereinforcing means 40 and 4|, I am enabled to distribute the stressesdelivered to the piston body considered as a whole, and to reinforceeach separate member of the piston body, especially near the opposingfaces of the body members; and by making the body in sections, each ofwhich includes only one reinforcing ring, I am enabled to simplify themolding process and to achieve a highly efficient bond between the ringand the rubber body.

Fig. 1 shows the piston assembled on the piston rod ID with theinterlocking parts of the piston clamped together between the conicalshoulders l2 and I5. It will be apparent that by simply removing thepiston rod nut l4, the interlocking members of the piston may be freelyseparated and disengaged from each other, as indicated in Fig. 2.

Figs. 3 and 4 have in common the same hub member 45 and the sameintermediate annular member 46, but the piston body member 41 of Fig. 3islarger in diameter than the piston body member 48 of Fig. 4.

The piston rod 50 of Fig. 5 has a tapered portion 5| and a threaded end52 on which end is mounted a lock nut 53 and a piston nut 54 having theusual conical shoulder 55. The hub member 56 at the inner end of thepiston may be shrunk or driven onto the tapered portion 5| of the pistonrod in a permanent manner. As shown in the drawing, the intermediateannular member 59 and the hub member 80 at the outer end of.the pistonfit loosely over the tapared portion 5| of the piston rod to permit freemovement in the assembling or dismantling of the piston. In the normalassembled position of the parts, the core assembly is held together bypressure exerted between the conical shoulder and the hub member 56, thereinforcing ring 6| of a body member 62 being interlocked with the hubmember 56 and the annularmember 59, and, in similar manner, thereinforcing ring 63 of the body, member 54 being interlocked with thehub member and the intermediate annular member 59.

The preferred form of my invention, set forth specifically herein forthe purpose of complete disclosure, suggests a wide range of structuralmodifications and changes without departing from the spirit of myinvention. I reserve the right to all such changes and modificationsthat properly come within the scope of my appended claims. a

I claim as my invention:

1. A piston of the class described,.having in combination: a coreassembly providing walls forming a plurality of peripheral recesses; aplurality of resilient piston bodies adapted for mounting on said coreassembly; and annular rigid reinforcement members permanently embeddedin said bodies, said members being complementary to said recesses to bepositively confined by the walls thereof and thereby locked againstaxial movement in either direction, said core assembly being separableat said recesses to release said reinforcement members for replacementof piston bodies.

2. A piston of the class described, having in combination: a flanged hubmember at one end of the piston; a second flanged hub member at theopposite end of the piston; an intermediate annular member forming withsaid hub members a core assembly; a central radialflange integral withsaid intermediate annular member, said hub members and intermediateannular member being constructed and arranged to form cooperatively twoperipheral recesses separated by said flange; two complementary pistonbody members of. yielding material, each adapted for mounting on one ofsaid hub members to extend over said intermediate annular member; andtwo rigid annular reinforcing members, one permanently embedded in eachof said body members, said reinforcing members being complementary tosaid recesses and adapted to seat therein abutting said radial flange.

3. In a piston construction, an interlocking combination comprising: twohub members, each having a cylindrical portion and an end flange; anintermediate annular means forming with said hub members a coreassembly, said intermediate means having a cylindrical portion ofsmaller diameter than said hub members and having a central flangewhereby two annular recesses are formed by said central flange andcylindrical portions; and a pair of complementary body members adaptedto be gripped between said end flanges, each-of said body members havinginwardly disposed flanges complementary to said annular recesses.

4. In a piston construction, an interlocking combination comprising: twohub members, each having a cylindrical portion and an end flange; anintermediate annular means forming with said hub members a coreassembly, said intermediate means having a cylindrical portion 01'smaller diameter than said hub members and having a central flangewhereby two annular recesses are formed by said central flange andcylindrical portions;- apair of complementary body members of yieldingmaterial adapted to be gripped between said end flanges and to embracesaid cylindrical portions of the hub members and said central flange;and two rigid annular reinforcing members, one embedded permanently ineach of said body members, each of said reinforcing members having anannular portion embracing the inner end of the cylindrical portion ofthe corresponding hub member and having also an inwardly disposedannular flange portion abutting said central flange and seating in oneof said annular recesses.

5. A piston of the class described, having in combination: a flanged hubmember for one end of the piston; an intermediate annular member inaxial alignment therewith, said hub member and annular member beingconstructed and arranged cooperatively to form a peripheral recesshaving two oppositely facing annular walls; a piston body of yieldingmaterial adapted to bemounted on one of said members; a rigid reberbeing constructed and arranged cooperative- 1y to form a secondperipheral recess having two oppositely facing annular wa11s;' a'secondpiston body of yielding material adapted to be mounted on said secondhub memberi and a second rigid reinforcement member permanently embeddedin said second piston body member and adapted to seat in said secondrecess and-- 5 abut both said walls thereof. a

' GEORGE c. WELLS.

